This invention relates to solenoid valves and, more particularly, to an improved valve of the type wherein a single molded plastic body element is configured to form an inlet connection, a guide tube for the solenoid armature, a valve seat, and an outlet.
U.S. Pat. No. 3,529,806, to Kozel, discloses a solenoid valve which includes a molded one-piece plastic valve body having at one end a relatively large diameter cup-shaped housing and a relatively small diameter elongated tubular extension formed integrally with and projecting outwardly from the housing. A valve seat is formed within the extension and the extension acts as a guide tube for the solenoid armature, with the solenoid coil surrounding the extension. Fluid enters the valve through the cup-shaped housing which has therein a resilient deformable flow rate control member. A first metal insert press fit within the cup-shaped housing acts as a seat for the flow control member and as a stop for a spring which biases the plunger toward the valve seat. A second metal insert press fit within the cup-shaped housing on the other side of the flow control member from the first metal insert acts as a support for a filter screen. This design is disadvantageous in that swelling of the plastic body or shavings produced during insertion of the metal inserts can result in undesirable loosening of the parts, resulting in poor flow control and/or bypass leakage.
It is therefore a primary object of this invention to provide a solenoid valve of the type described which does not have the disadvantages enumerated above.
A particular application of the above-described valve is in an ice cube maker of a refrigerator. If the consumer energizes the refrigerator and neglects to turn on or connect a water supply to the valve, when the valve is energized the plunger will pass magnetic neutral and then accellerate backwards, impacting and chattering against the valve seat. This significantly reduces the life of the valve as well as producing undesirable noise.
Accordingly, it is another object of this invention to eliminate plunger "chattering" when the valve is energized with no liquid present.